District heating and cooling/community energy systems (sometimes also called district energy or DE) are technologies designed to deliver hot or chilled water from a central thermal source (preferably heat pumps, which are among the most efficient sources of energy) through pipes to customers for space heating and cooling. DE systems (DESs) offer energy savings, end-user cost reduction, substantial reduction of greenhouse gases (GHG), improved air quality, reduction of electric peak, retention of dollars in the communities, improvement of balance of payments, increase of employment, economic development/revitalization, new business opportunities, and national security. DE is extensively used throughout Europe, where national policies promote its use (Denmark, for example, relies on DE for more than 60% of space heat conditioning requirements). DESs have the flexibility to:
Throughout the last several decades, various DESs have been constructed in New York under the sponsorship of NYSERDA. A number of these systems have been integrated with DE supply to communities. This paper presents analysis of successful and unsuccessful DESs.